NASA scientists are set to launch an exploratory rover to the south pole of the moon late next year, with a goal of finding pockets of water that can be used for future manned missions to the lunar surface in 2024 and beyond.
The plan, announced at a press conference Monday, is to land the golf cart-sized robot along the western edge of the Nobile crater, a large impact crater spanning roughly 45 miles that is mostly shrouded in darkness. Scientists at NASA Ames in Mountain View are managing the mission, and will have to navigate the robot through challenging and frigid terrain during its 100-day trek across the contours of the crater.
The rover's mission is to create a first-of-its-kind, detailed resource map on the moon's south pole, with an eye toward finding water and other valuable substances on or just below the lunar surface. The vehicle, dubbed the Volatiles Investigating Polar Exploration Rover (VIPER), is equipped with a one-meter drill capable of boring into the surface in the search for water.
NASA has only studied the lunar surface and the potential for valuable resources from afar using orbiters and satellites up until now, making VIPER the first chance to test those theories and see what's truly there, said Lori Glaze, director of NASA's Planetary Science Division.
"All of that will change once VIPER lands," Glaze said. "The rover is going to get up close and personal with the soil."
The rover has long been part of NASA's Artemis program, a human spaceflight mission with an emphasis on finding ways to sustain a human presence on the moon once they get there. VIPER's discoveries will help figure out where astronauts can feasibly land and harvest resources during extended missions, and frozen water — with its potential to be converted into oxygen and fuel — is among the top priority finds.
In June last year, NASA awarded the private company Astrobotic a $200 million contract to assist in delivering VIPER to the south pole on a lander that will be launched from Earth.
Keeping the rover upright and powered is going to be a constant challenge as the 1,000-pound, four-wheeled robot traverses some of the most challenging conditions. Though the Nobile crater is the best of many options considered, it's still frigid, dark, hilly and craterous, said Daniel Andrews, the VIPER project manager at NASA Ames. The rover is solar powered and needs light to hit its solar panels, but the sun is so close to the horizon that it casts long shadows that will make it difficult for the driver to stick to bright spots.
The rover also needs to be built sturdy enough to withstand a huge range in temperatures. The permanently shadowed craters in the region are close to 50 degrees Kelvin, or about minus 370 degrees Fahrenheit, while the sun-bathed areas of Nobile can reach minus 10 degrees Fahrenheit.
"It's extremely cold in the dark but also fairly warm in the daylight, and our little rover needs to be able to operate in both of those extremes and everywhere in between," Andrews said.
Unlike the Mars rover with its classic six-wheeled "rocker-bogie" suspension design, VIPER has more motion capabilities, with four independently moving wheels that can move side-to-side like a crab. The alternative design, bolstered by its relatively fast speed, is important as the lunar rover fights to keep its solar panels in the sunlight among shifting shadows.
Another perk of the system is that VIPER will be sending back data in near real-time, unlike other exploratory missions where scientists have to wait days or even weeks. That means the team at Ames will be able to analyze data quickly and make adjustments to maximize how much research they can pull off before the rover is out of commission — which is both a boon and a challenge. Scientists will have to make swift decisions and adjust quickly based on the results coming in.
The rover will be landing on the moon's surface in late 2023 packing not only a drill but spectrometers that can record exactly what comes up, said Tony Colaprete, lead project scientist for VIPER at NASA Ames. It will be able to track the amount of hydrogen in the ground and the depth that it's buried, and detect any gases coming off a recently bored hole in the surface. The equipment provides enough info to tell scientists how much ice is present and in what form.
Though there's a strong probability that the lunar rover will find ice on its course, it's not a slam dunk. The data collected to date has detected ice on the moon's surface on a larger, orbital perspective, but it's going to take a rover directly on the surface to find ice on a human scale and finally put observations and theories to the test.
"This is exactly why we're going," Colaprete said. "We know there's water ice there, we know some of it is at the surface and some is below the surface. Exactly where and how much and how it's distributed between surface and subsurface is a large unknown."